15
5. Accessories for Electrical Type Solenoids: The model
code (Table 2) indicates the type of accessories used on
directional valves. Obtain a parts and service drawing for
your particular model (see Table 1). Most accessories
pertain to the pilot section. The most common types of
accessories are discussed in the following paragraphs (A
through F).
A. Hazardous Location Solenoids: This type of is used
at locations where added protection from electrical shortage
failure is mandatory, the solenoid housing is designed to
completely enclose all wiring connections to the valve.
Hazardous location valves are underwriters approved Class
1, Group D or Class 2, Group E-F-G, for 155 and 230 volts,
60 Hz service.
B. Monitor (Limit) Switch Feature: The monitor switch
feature can be incorporate into a basic spring offset
directional valve. The switch monitors pilot valve spool
position and an be wired into control circuits. This permits
electrical interlocking of various hydraulic controlled motions
without resorting to external mechanical arrangements. The
monitor switch is a single pole, double throw contact
arrangement with ‘‘A’’-normally closed and ‘‘B’’- normally
open. Switch ratings are noted on installation drawing (Table
1). The monitor switch housing does not provide a manual
plunger for operation of the switch or valve.
C. Insta-Plug Connectors: Pilot valves can be supplied
with electrical connectors called insta-plugs. These
connectors allow quick disconnect of electrical power from
the valve. The following data pertains to the insta-plug feature:
PA-
A prefix of PA in the model code indicates the
male plug section of the insta-plug feature is included
on the valve.
PB-
A prefix of PB in the model code indicates
both the male plug and female receptacle are
included with the valve. the insta-plug feature is
available on both the DG4V-3 and DG4S4-01 series
directional valves.
Wiring Note
Connect white wires to ‘‘A’’ solenoid and black wires to
the ‘‘B’’ solenoid. Refer to parts drawing (Table 1) for
additional data.
D. Brad Harrison Connectors: Brad Harrison connectors
thread into the
1
/
2
” NPTF opening in the wiring housing of a
DG4V-3 or a DG4S4-01 directional valve.
PA3-
A prefix of PA3 in the model code indicates
the three pin male connector is included with the
valve.
PA5-
A prefix of PA5 in the model code indicates
the five pin male connector is included with the valve.
Female Brad Harrison connectors are not available from
Vickers and must be supplied by the customer.
E. Solenoid Indicator Lights: Solenoid indicator lights are
available for installation on both the DG4V-3 and DG4S4-01
series directional valves. Indicator lights are connected
across the solenoids and will light when voltage is present at
the solenoid. This gives an indication to the technician which
solenoid is energized and aids in troubleshooting a system.
Refer to the appropriate parts drawing for additional
information.
Figure 13b. Typical DG4V4-01-C-10
Pilot Spool
Body
Terminal Box
Push Pin
Spring
Core Tube
Spool Stop
Plug-in
Coil
Manual override plunger
Section V - Internal Valve Functions
A. General
To insure the proper application of a two stage valve, pilot
pressure, pilot drain and integral check valve options must
be considered. The following paragraphs (B through D)
discuss these options.
B. Pilot Pressure
1. Internal Pilot Pressure (Standard): Internal pilot pressure
can be obtained in two ways and must be tailored for the
application. Models with closed center type spools
automatically provide internal pilot pressure. Models that use
open center spools require a check valve in the pressure (P)
port to maintain minimum pilot pressure. In most cases,
maximum internal pilot pressure is rated to 210 bar
maximum (3000 PSI). Minimum pilot pressure ratings are
noted in the installation drawings (see Table 1).
2. External Pilot Pressure: When pilot pressure from a
separate source is used, it must be connected to the ‘‘X’’ port
(external pilot pressure connection). Models that use
external pilot pressure do not require a check valve at the
pressure port. External pilot pressure models are identified
with the letter ‘‘E’’ stamped in the unit nameplate (i.e.
DG5V-10-S-2C-*-E-M-*-10). See installation drawings for
maximum external pilot pressure.
